html,body {
  font-family: monospace;
  font-size: 18px;
}

canvas {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  max-width: 100%;
  max-height: 100%;
  background: #282d34;
  box-sizing: border-box;
  border-radius: 2px;
}